JPS6017884B2 - road marking sheet material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to sheet materials that can be releasably applied to paved surfaces to provide temporary road markings.

It is often necessary to temporarily place signs on paved roads for traffic guidance.

Signs placed in construction zones to direct traffic to other lanes or roads should be removed when construction is complete so as not to misdirect subsequent traffic. Such temporary signs require a combination of competing properties: First, the sign should be clearly visible during the entire period of use, e.g. during a construction period that may last more than a year, in an appropriate location. be. Second, it should be removable by practical techniques so as to leave virtually no residue that would misdirect subsequent traffic. All previous temporary road markings have been extremely unsatisfactory.

Painted signs were the most common construction zone signs, but attempts to remove or erase the signs by grinding or painting over the signs at the end of the construction period were ineffective and unprofitable. Road marking tapes made using crepe paper supports have been commercially available for a limited time as an alternative to painted markings (see U.S. Pat. No. 3,915,771 to Ca-Seke et al.). These tapes were to be removed with a flame at the end of their useful life. However, such tapes have proven impractical and are no longer commercially available. Another conventional road marking tape has embedded a nonwoven fiber web as reinforcement in a layer of pressure sensitive adhesive carried on a support.

However, this tape was not easily removed because the metal foil support in the tape and the glass fibers in the reinforcement in the tape were cut under heavy road traffic. As a result, the tape could not be removed as a large continuous strip. Another reinforced road marking tape is taught in U.S. Pat. No. 4,146,635 to Eigenmann.

The reinforcement is described as a ``non-extensible intermediate layer'' such as a ``film of highly tensile resistant polymeric resin'' or ``a nonwoven fibrous structure impregnated with a highly tensile resistant resin.'' This tape is not intended to remove scales, but will stick to roads that have a bituminous reactive layer. Non-extensibility of the reinforcing agent is said to be desirable as it increases the tape's resistance to movement on the road under road traffic; This poor adhesiveness results in distinctly poor adhesion in Fujiwang adhesive road marking sheet materials. Sensitive E adhesive tapes, which are useful for packaging, sealing, etc., but not for road markings, are reinforced with a sheet embedded in the adhesive to strengthen the tape and make it removable. [See Kellgen, US Pat. No. 2,444,83]. However, such conventional tapes have not been useful for road markings, and the reinforcing sheet in the tape has been a paper that does not have the low recovery elongation properties necessary for road marking sheet materials. In short, although the need for improvements in temporary road markings was recognized, prior to the present invention, no technology exhibited the necessary features.

The present invention provides a new road marking sheet material that can be applied to roads and removed when the need for the marking is over.

Briefly summarized, this new road marking sheet material
a Distributed so as to extend in multiple directions, with an average of about 5
consisting of durable throat-resistant fibers separated by no more than the legs, b having a trapezoidal tear strength of at least approximately 2 kg in any direction (
(as described herein) and a stretchable porous fibrous web exhibiting at least 20% elongation before breaking: 2 polymeric layers (partially embedded in the top surface of the layer) disposed on the web and forming the outer surface of the web; A retroreflection that partially protrudes from the top surface (
(retroreflective) having microspheres): and 3 forming the outer bottom surface of the sheet material and having at least 0 per section of width of the sheet material.
．． 2k9, a pressure adhesive layer of at least 50 mm thick disposed beneath the fibrous web to produce adhesion of the sheet material to the steel substrate in a 18-pin peel test, said sheet material having a width of Approximately 1.5 kQ per width melon when measured 30 minutes after being stretched 5% and then immediately relaxed by 7.5% of the stretched amount.
It has a residual force of less than o.

In a preferred embodiment, a fibrous web is incorporated into the adhesive layer on the support.

The fiber web is generally embedded in an intermediate location such that an adhesive layer is present between the support and the web, and 50 or more layers of adhesive are located on the side of the fiber web remote from the support. do. It has been found that the sheet material of the present invention provides a combination of properties that, to our knowledge, have never been provided before.

First, the sheet materials of the present invention have been found to provide excellent lasting adhesion. One of the rationales for this improved adhesion is that the fibrous web used in the sheet material of the present invention exhibits low recovery elongation properties. That is, it exhibits low residual force and significant elongation at break after stretching. The sheet material of the invention is therefore well suited for roads and
Only a very small force is generated to shrink it into a predetermined shape and separate it from the road. Although the sheet material of the present invention has good adhesion, it is generally practicable and effectively removable even after long periods on the road (by lifting the corners of the sheet material and peeling off at least in large strips). (typically removed by).

However, during the period of use, the sheet material remains in place as a clear visible indicator. Furthermore, the sheet material can be applied quickly and easily. The drawing is a cross-sectional view of the sheet material of the invention.

The illustrated sheet material 10' includes a support 11 comprising a polymeric layer 1 in which retroreflective glass microspheres 13 and irregularly shaped anti-skid particles 14 are partially embedded.
Contains 2. An adhesive layer 15 is supported on the bottom surface of the support;
The elastic fibrous web 16 is embedded in and impregnated by the adhesive layer. Layer 17 of the twill adhesive layer is placed between the support and the fibrous web, and layer 18 is placed on the side of the web remote from the support so as to form the outer bottom surface of the sheet material. A liner 19, shown in dotted lines, may be included in the sheet material as a removable cover for the adhesive layer. The support in the road marking sheet material of the present invention should be made from a flexible material so as to conform to irregular road surfaces and to minimize the forces that tend to cause it to contract out of its conforming shape.

Jorgensen U.S. Patent No. 411
Low modulus, deformable polymer sheets such as those taught in No. 71 are preferred.

Such sheets typically contain elastomeric precursors,
That is, it can be tempered or hardened to form an elastomer, but
It consists of components that are not processed in the sheet and thus allow the sheet to exhibit the desired deformability. Particularly useful elastomeric precursors are acrylonitrile-butadiene polymers, rollable urethane polymers, and neoprene. Deformability can be further promoted by including extender resins in these sheets, such as chlorinated paraffins, hydrocarbon resins or polystyrene, where the elastomer precursor component is present in the sheet at least 5% by weight of the polymer component.
It is preferable that it extends to. dead-so
ft) Aluminum foil is a useful support material as it is flexible enough to be folded onto itself and retain its folded shape, but its strength against the sheet material during removal from the roadway few. The polymer-based sheet or metal foil contains glass microspheres and optionally other particulate matter partially embedded in the polymer layer and partially protruding above the polymer layer, as shown in FIG. The polymer layer 12 can have the following properties.

Additionally, microspheres or other particulate materials may be embedded within a polymer-based support. The polymer layer may consist of polymers such as pinyl-based polymers, epoxy-based polymers, polyurethanes, and polyesters. It is also typical to tint the polymer layer to impart color to the sheet material, and to provide a continuous color when the polymer layer is removed by traffic abrasion, the polymer is attached to the substrate beneath the polymer layer. Typically, the sheets are colored the same color. The adhesive layer on the bottom side of the sheet material of the invention is preferably a pressure sensitive adhesive so that the sheet material can be pressed against the road surface and removably adhered thereto.

The adhesive layer has an adhesive strength of at least 0.2 k9 per width, preferably at least 0.5 k9 per width, with a peel resistance of 18 and as described in ASTM DIOO 0.36 to Chapter 1. should occur. In this test,
A steel panel is used as a base panel to measure adhesive strength. A suitable adhesive is Freeman
) rubber-resin adhesives and Ullrich adhesives such as those taught in U.S. Pat. No. 51,537 of
U.S. Patent Re. 24906, as taught in US Pat. It generally contains at least about 1/4 inch adhesive to provide good adhesion to the connecting surfaces (which may have large surface irregularities). The fiber web is preferably embedded in the adhesive layer, which is sufficiently porous and sufficiently separates the fibers to allow the attachment agent to saturate, or surround, the individual fibers of the web.

On the other hand, if the fibers are separated by more than about 5 kites on average, the support will be compressed through the web under the pressure of road traffic and any attempt to lift the sheet material from the road surface will result in
Parts of the support will remain adhered to the road surface. Typically, the fibers are separated by less than one rib on average. If the fibrous web is embedded in the adhesive layer, removing the tape removes at least a large portion of the adhesive from the roadway.

However, loose webs work well if they are embedded in a support rather than in an adhesive, for example by solution impregnating the web with a polymeric material so as to leave a polymer layer on the web in which the microspheres can be embedded. Adhesive removal can also be achieved. The fibrous web should be sufficiently stretchable so that it can be stretched by at least 20%, preferably at least 50%, before breaking.

Preferred fiber webs consist of non-woven polyester with good durability and weather resistance ("non-woven polyester" refers to continuous filament polyester fibers that are randomly arranged, highly dispersed, and bonded with filament connections). sheet products). Particularly preferred are crimped fiber forms that produce higher elongations and lower residual forces when stretched. Other nonwoven sheets with randomly distributed fibers and fibers of various other polymers (ie, polyolefins and acrylics) are also useful. Stretch woven fabrics can also be used. In all of the above forms, the fibers extend in multiple directions, which distributes the fibers in a way that contributes to multidirectional tensile strength that increases removability.

The web was tested for trapezoidal tear strength (ASTM DII17, 14).
chapter) should have a strength of at least 2 kg in any direction, preferably at least 5k9. Height 75 to sample
Legs, parallel sides (bottom and top) dimensions 100 ribs and 25
Marked with a trapezoid of ribs, the non-parallel sides of the specimen are held in the jaws of a tensile tester and a continuously increasing load is applied so that the tear widens in the specimen. The absolute force measured is referred to herein as trapezoidal tear strength. Strength measurements as described above determine the resistance of the sheet material to cuts or other cuts that it may experience on the road and which may cause the sheet material to tear during removal. The finished sheet material with fiber web has a width of 1
It has a tensile strength of at least 0.5k9 per width, preferably at least lk9 per width.

Despite having good tensile strength, the residual force of the sheet material should be low in order to maintain good adaptation to road surface irregularities. Since the adhesive has some elasticity, the residual force can be measured after it has relaxed slightly from the stretched state, for example after 7.5% relaxation of the stretched leather. Also, in order to equilibrate the conditions, the sample is stretched and the residual force is measured 30 minutes after relaxation. In such tests, the sheet material of the present invention was found to have a
．． It should exhibit a residual force of less than 5k9. Although the residual strength just described characterizes the finished sheet material, the reinforcing web itself exhibits such properties independently of the rest of the sheet material.

In manufacturing the sheet materials of the present invention, the fibrous web is typically impregnated with adhesive by passing the web through a solution of the adhesive.

In this way the reinforcing web can be provided with sufficient adhesive to adhere to the support. Alternatively, the support can be coated with an adhesive layer before applying the impregnated web, and a further adhesive can be applied to form the bottom of the adhesive layer. Next, the present invention will be explained in detail based on examples.

The support as described in U.S. Pat. Manufactured using. Average diameter approximately 0
．． Four side glass microspheres and sand grains of approximately the same size were scattered and partially embedded in the vinyl film. Comprised of continuous non-woven polyester fibers, it has a weight of 805 mm/h, a tensile tear strength of 5.6 k9 and 7.5 k9 in mutually perpendicular directions, and an elongation of more than 100% before break [Reemay 2431, DuPont) was passed through an adhesive solution as described in US Pat. No. 51,537, Example 5, rolled onto a release liner, and dried in an oven.

Coating a layer of the same adhesive onto the release liner and drying, then a) laminating one layer of adhesive on the bottom side of the prefabricated support and removing the release liner, and b) laminating one layer of twilling. The adhesive-impregnated web was applied to the exposed side of the adhesive layer, the release liner was removed, and c) an additional layer of adhesive was applied to the exposed side of the adhesive-impregnated web. The finished composite layer of adhesive was approximately 0.4 ribs thick. The completed sheet material is 1
It showed a tensile strength higher than 4k9 per arc and a residual force of about lk9 per arc.

Samples of the sheet material were cut into strips of approximately one thread wide fence tape and applied to a test road surface carrying high density vehicles. The tape remained in place as a visible marker for over a year, at which time it could be easily removed with a larger strip by peeling.

[Brief explanation of drawings]

The drawing is a cross-sectional view of the sheet material of the invention.

Claims (1)

Claims: 1. A road marking sheet material that can be applied to a paved surface and removed when the need for marking has ended, comprising: 1 distributed in a plurality of directions and with an average a stretchable porous fibrous web of durable weather-resistant fibers separated by no more than about 5 mm, the web exhibiting a trapezoidal tear strength of at least about 2 kg in any direction and an elongation before break of at least 20%; 2 a polymer layer disposed on the web and forming the outer surface of the sheet material having retroreflective microspheres partially embedded in and partially protruding from the top surface of the layer; a thickness that forms the outer bottom surface of the sheet material and is located below the fibrous web to produce an adhesion force of the sheet material to the steel substrate in a 180° peel test of at least 0.2 kg per cm width of the sheet material; a pressure-sensitive adhesive layer of at least 50 μm, the sheet material having a width of at least 0.5 μm per cm
kg, and having a residual force of less than about 1.5 kg per cm width when measured 30 minutes after being stretched 5% and then immediately relaxed by 7.5% of the stretched amount. road marking sheet material. 2. A sheet material according to claim 1, in which the fibrous web is embedded in the adhesive layer. 3. The sheet material according to claim 1 or 2, wherein the fibrous web is made of nonwoven continuous polyester fibers. 4. The sheet material according to any one of claims 1 to 3, wherein the fibrous web is made of crimped fibers. 5. Sheet material according to claims 1 to 4, wherein the fibrous web exhibits an elongation of at least 50% before breaking. 6. A sheet material according to claims 1 to 5, comprising a support consisting of an unvulcanized elastomeric precursor, an extender resin and a filler.